Other intangible assets, net (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Assets subject to amortization Customer related intangibles	Dec. 31, 2011 Assets subject to amortization Customer related intangibles	Jun. 30, 2012 Assets subject to amortization Unpatented technology	Dec. 31, 2011 Assets subject to amortization Unpatented technology	Jun. 30, 2012 Assets subject to amortization Software	Dec. 31, 2011 Assets subject to amortization Software	Jun. 30, 2012 Assets subject to amortization Patents and other protective rights	Dec. 31, 2011 Assets subject to amortization Patents and other protective rights	Jun. 30, 2012 Assets subject to amortization Trade secrets	Dec. 31, 2011 Assets subject to amortization Trade secrets	Jun. 30, 2012 Assets not subject to amortization Trade names	Dec. 31, 2011 Assets not subject to amortization Trade names
Schedule Of Other Intangible Assets By Major Class [Line Items]
Cost			$ 1,030,543	$ 1,022,134	$ 203,621	$ 193,915	$ 49,396	$ 49,395	$ 27,654	$ 25,398	$ 1,500	$ 1,500	$ 230,691	$ 231,207
Accumulated amortization			(332,805)	(302,156)	(86,591)	(72,358)	(38,330)	(35,833)	(19,124)	(17,699)	(1,431)	(1,361)	0	0
Net book value			697,738	719,978	117,030	121,557	11,066	13,562	8,530	7,699	69	139	230,691	231,207
Amortization expense of other intangible assets	$ 50,336	$ 48,376